Chinese smartphone maker Coolpad, that also has a presence in India, has filed multiple cases against local rival Xiaomi for alleged patent infringement. The firm has demanded that Xiaomi should stop production as well as sale of its smartphones.

“Yulong demanded that the Xiaomi companies should immediately stop production or offering for sale and current sale of some of the smartphone models, including the Xiaomi 6, Xiaomi Max2, Xiaomi Note3, Xiaomi 5X, Redmi Note4X and Mi MIX2,” Coolpad said in a statement.

The patents involved in this lawsuit are systematic interactions or UI type patents. They all involve basic communication, display and interactive functions of mobile phones, and are difficult to circumvented or replaced.

Coolpad has filed the patent infringement cases against three group firms of Xiaomi including Xiaomi Telecom Technology Co, Xiaomi Technology Co and Xiaomi Factory Co, in a court in Jiangsu province of China.

Yulong, the parent company of Coolpad, had filed a similar legal case against Xiaomi in a Shenzhen court in January 2018 as well.

“It is because the IP (intellectual property) protection environment in China has improved, Coolpad launched the lawsuit in January this year,” the firm’s global chief patent officer Nancy Zhang told a press conference on Friday.

The Chinese firm has alleged that Xiaomi violated its patented multi-SIM card design and other technology related to user interface. It demanded that Xiaomi compensate it for losses due to the alleged infringement.

“On 12th January this year, Yulong Computer Communication Technology (Shenzhen) Co., Ltd., submitted a lawsuit request to Shenzhen Intermediate People’s Court and was accepted on January 25, 2018. Zhang, said, ”Since 2014, Coolpad has repeatedly sent warning letters to Xiaomi, stating that the mobile phone it sold was suspected of infringing on Coolpad’s patent rights and proposed friendly negotiation, but did not receive a response. In desperation, Coolpad could only seek redress through legal channels.”

Coolpad Group CEO Jiang Chao said, “If cumulative achievements of thousands of R&D engineers’ working from day to night for 25 years, are arbitrarily plagiarized and not pursued, we should reflect on our tolerance and this will ultimately harm innovation in the entire nation and the future generations.”

The company also said that it hopes that Xiaomi will stop patent infringement and actively cooperate with it to promote industrial progress. Litigation is a legal remedy for resolving intellectual property disputes.

“Coolpad is looking forward to working with Xiaomi to find a better solution, strengthen intellectual property protection and create a good business environment,” the company said in a statement.